How else to explain the Baltimore Orioles beating the playoff-tested New York Yankees, and rookie Wei-Yin Chen outpitching 40-year-old Andy Pettitte?

With Chen leading the way, the Orioles squeezed out a 3-2 victory on Monday night to even their AL division series at one game apiece.

Chris Davis drove in two runs for the wild-card Orioles, who used the same formula that got them into the postseason for the first time in 15 years: a magnificent bullpen and an ability to win tight games. Baltimore was 29-9 in one-run decisions during the regular season and 74-0 when leading after seven innings.

Major league saves leader Jim Johnson, roughed up for five runs in a Game 1 loss, came back to pitch a perfect ninth to close it out.

The rest of the best-of-five series is at Yankee Stadium, beginning with Game 3 on Wednesday. Hiroki Kuroda will start for AL East champion New York against rookie Miguel Gonzalez.

“It means everything,” Davis said of the win. “You definitely don’t want to go into New York in a five-game series down two games. This is big — having the day off tomorrow, hopefully building some momentum, and we can take that into New York.”

Chen gave up two runs, one earned, and eight hits over 6 1-3 innings. The Taiwan native, who pitched previously in Japan, was 1-2 with a 5.25 ERA in four outings against New York this season, including two in September in which he yielded a total of 11 runs over 11 1-3 innings.

“I thought he pitched inside pretty effectively tonight to some of our right-handed hitters,” Yankees manager Joe Girardi said. “It seemed like Baltimore and us have kind of gone back and forth all year and that’s what we did here.”

The teams split the season series 9-9.

Chen left with a 3-2 lead, and the bullpen made it stand up. Johnson retired Derek Jeter and Ichiro Suzuki on grounders and struck out Alex Rodriguez to end it in front of a rollicking crowd at Camden Yards.

Much earlier, Suzuki’s deft dancing at the plate put the Yankees ahead.

Pettitte, whose 19 wins and 43 starts are the most in postseason history, allowed three runs and seven hits in seven-plus innings. He came out of retirement before this season to pitch again in the playoffs, and although he was effective, Chen was better.

Pettitte, however, got little offensive backing. New York stranded 10 and went 2 for 8 with runners in scoring position.

After Davis hit a two-run single to put Baltimore up 2-1 in the third inning, Matt Wieters led off the sixth with a double and scored on a single by Mark Reynolds to make it 3-1.

But New York came right back in the seventh. Eduardo Nunez got a double when Davis couldn’t catch his blooper to right and Jeter followed with an RBI single. After Suzuki hit into a fielder’s choice, Darren O’Day replaced Chen and struck out Rodriguez as Suzuki stole second. Brian Matusz came in and issued an intentional walk to Robinson Cano to set up a matchup with Nick Swisher.

Swisher was 1 for 18 lifetime against Matusz and 1 for his last 32 in postseason play with runners in scoring position. A wild pitch moved up the runners, but the percentages held up, as Swisher hit a routine fly ball to left.

The Yankees used the nifty footwork of Suzuki to take a 1-0 first-inning lead, and it had nothing to do with his speed on the basepaths.

Jeter led off the game with a single and Suzuki reached when Reynolds fumbled a bare-hand pickup at first base for an error.

Rodriguez hit a low line drive at second baseman Robert Andino, who caught it and doubled up Jeter. Cano followed with a drive to the base of the right-field wall for a double. The relay from Davis to Andino to Wieters beat Suzuki to the plate by plenty, but he dodged the tag coming toward home.

Suzuki then circled around the batter’s box, juked around the catcher’s desperate lunge and touched the plate an instant before Wieters’ glove found its mark.

Pettitte retired the first eight batters before Andino hit a bloop single with two outs in the third. Nate McLouth also singled, and a four-pitch walk to J.J. Hardy loaded the bases for Davis, who lined a single to right.

Adam Jones followed by grounding a single just beyond the reach of Jeter at shortstop, but Hardy stopped at third after failing to spot third-base coach DeMarlo Hale waving him home. Wieters then popped out with the bases loaded.

In the fourth, the Yankees used two singles and a walk to load the bases with one out. Nunez popped out before Jeter bounced into a forceout.